Fluorine-containing polyfunctional (meth) acrylate composition low refractivity material and reflection reducing film

ABSTRACT

Fluorine-containing polyfunctional (meth)acrylate represented by the formula (1), as well as a composition, a low refractivity material and a reflection reducing film in which the (meth)acrylate is utilized: ##STR1## wherein X stands for a fluoroalkyl group of C1-14 having 3 or more F, or a fluorocycloalkyl group of C3-14 having 4 or more F; Y 1 , Y 2 , and Y 3  stand for H, an acryloyl group or a methacryloyl group, and at least two of Y 1 , Y 2 , and Y 3  stand for an acryloyl group or a methacryloyl group; Z stands for H or an alkyl group of C1-3; and n and m is an integer of 0 or 1, and n+m=1.

This application is a national stage application for PCT JP97/01952filed Jun. 9, 1997 and entitled to the priority the Japaneseapplications 8-147139, 8-244963, 8-292640, 8-296509, filed Jun. 10,1996, Sep. 17, 1996, Nov. 5, 1996, and Nov. 8, 1996, respectively, thepriority of which is claimed.

BACKGROUND ART

The present invention relates to novel fluorine-containingpolyfunctional (meth)acrylate; compositions which can be used as astarting material for preparing a low refractivity material having bothhigh surface hardness and low refractive index and being able to beapplied to the surface of various kinds of substrates; a lowrefractivity material prepared by curing the composition bypolymerization; and a reflection reducing film provided with the lowrefractivity material.

Compounds having a fluorine atom have low refractive index, and can beused for antireflection films or a clad material for optical fibers. Ineither applications, the lower the refractive index of the compound, thebetter the property of the products. There are proposed, for example,application of fluorine-containing (meth)acrylate polymers, copolymersof fluorine-containing (meth)acrylate with other monomers,tetrafluoroethylene polymers, copolymers of vinylidene fluoride andtetrafluoroethylene, or copolymers of vinylidene fluoride andhexafluoropropylene to optical fibers (Japanese Laid-open PatentApplication Nos. 59-84203, 59-84204, 59-98116, 59-147011, and59-204002).

Recently, there has attempted to apply solvent-solublefluorine-containing polymers having low refractive index such asfluoroalkyl acrylate polymers, fluoroalkyl methacrylate polymers, oramorphous perfluoro resins such as CYTOP (trade name) manufactured byASAHI GLASS COMPANY, or TEFRON AF (trade name) manufactured by E.I. duPont de Nemours and Co. to reflection reducing films (Japanese Laid-openPatent Application Nos. 64-16873, 1-149808, and 6-115023).

These fluorine-containing resins, however, are non-cross-linked resins,and thus have low surface hardness after curing, inferior abrasionresistance, and insufficient adhesion.

For the purpose of improving the surface hardness, there has beenproposed cross-linked polymers prepared from a suitable mixture offluorine-containing monofunctional (meth)acrylate or fluorine-containingbifunctional (meth)acrylate and polyfunctional (meth)acrylate notcontaining fluorine (Japanese Laid-open Patent Application Nos.58-105943, 62-199643, and 62-250047). The refractive index and thesurface hardness of these cross-linked polymers may be adjusted to someextent by suitably selecting the content of fluorine in thefluorine-containing (meth)acrylate, or the mixing ratio of thefluorine-containing (meth)acrylate to the polyfunctional (meth)acrylatenot containing fluorine. However, the fluorine-containing monofunctional(meth)acrylate and the polyfunctional (meth)acrylate are not compatible,and do not dissolve mutually at an arbitrary ratio. Therefore,sufficiently low refractive index cannot be achieved. On the contrary,the fluorine-containing bifunctional (meth)acrylate and thepolyfunctional (meth)acrylate mutually dissolve at an arbitrary ratio.However, if the content of fluorine atoms in the cross-linked polymer isincreased for reducing the refractive index, the cross-linking densityis lowered. Accordingly, it is impossible to suffice both the lowrefractive index and the high surface hardness, and it is difficult togive sufficient surface hardness to the optical fibers and thereflection reducing films. Further, sufficient adhesion cannot beachieved.

There is also proposed fluorine-containing hydroxy (meth)acrylate forthe purpose of improving the adhesion and for use as a starting materialfor other fluorine-containing (meth)acrylates (Japanese Laid-open PatentApplication Nos. 4-321660, 4-356443, and 4-356444). However, since thesecompounds are monofunctional (meth)acrylate, the surface hardness aftercuring is low, and the abrasion resistance is inferior.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide fluorine-containingpolyfunctional (meth)acrylate which gives fluorine compounds havingsufficiently low refractive index, sufficiently high surface hardness,and adhesion.

It is another object of the present invention to provide a lowrefractivity material having low refractive index and superior surfacehardness, a reflection reducing film, and fluorine-containing monomercompositions which can be used as a starting material for such materialand film.

According to the present invention, there is providedfluorine-containing polyfunctional (meth)acrylate represented by theformula (1): ##STR2## wherein X stands for a fluoroalkyl group having 1to 14 carbon atoms and 3 or more fluorine atoms, or a fluorocycloalkylgroup having 3 to 14 carbon atoms and 4 or more fluorine atoms; Y¹, Y²,and Y³ stand for a hydrogen atom, an acryloyl group or a methacryloylgroup, and at least two of Y¹, Y², and Y³ are the same or differentgroups and stand for an acryloyl group or a methacryloyl group; Z standsfor a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; and nand m stand for an integer of 0 or 1, and n+m=1.

According to the present invention, there is provided afluorine-containing monomer composition comprising 5 to 100% by weightof said fluorine-containing polyfunctional (meth)acrylate represented bythe formula (1) above.

According to the present invention, there is further provided acomposition comprising the fluorine-containing polyfunctional(meth)acrylate represented by the formula (1) above and powders of aninorganic compound in total of 5 to 100% by weight of the composition.

According to the present invention, there is further provided a lowrefractivity material having refractive index of 1.49 or lower preparedby a method comprising the step of curing the fluorine-containingmonomer composition or the composition containing the powders of aninorganic compound by polymerization.

According to the present invention, there is provided a reflectionreducing film comprising a transparent substrate, a layer of the lowrefractivity material above, and optionally at least one material layerbetween the transparent substrate and the layer of the low refractivitymaterial.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the results of the measurements of thespectral reflectance in Example 4-1.

FIG. 2 is a graph showing the results of the measurements of thespectral reflectance in Example 4-2.

FIG. 3 is a graph showing the results of the measurements of thespectral reflectance in Example 4-3.

FIG. 4 is a graph showing the results of the measurements of thespectral reflectance in Example 4-4.

FIG. 5 is a graph showing the results of the measurements of thespectral reflectance in Example 4-5.

FIG. 6 is a graph showing the results of the measurements of thespectral reflectance in Example 4-6.

FIG. 7 is a graph showing the results of the measurements of thespectral reflectance in Example 4-7.

FIG. 8 is a graph showing the results of the measurements of thespectral reflectance in Example 4-8.

FIG. 9 is a graph showing the results of the measurements of thespectral reflectance in Comparative Example 1.

FIG. 10 is a graph showing the results of the measurements of thespectral reflectance in Comparative Example 2.

FIG. 11 is a graph showing the results of the measurements of thespectral reflectance in Comparative Example 3.

FIG. 12 is a graph showing the results of the measurements of thespectral reflectance in Comparative Example 4.

FIG. 13 is a graph showing the results of the measurements of thespectral reflectance in Example 5-1.

FIG. 14 is a graph showing the results of the measurements of thespectral reflectance in Example 5-2.

FIG. 15 is a graph showing the results of the measurements of thespectral reflectance in Example 5-3.

FIG. 16 is a graph showing the results of the measurements of thespectral reflectance in Example 5-4.

FIG. 17 is a graph showing the results of the measurements of thespectral reflectance in Example 5-5.

FIG. 18 is a graph showing the results of the measurements of thespectral reflectance in Example 5-6.

FIG. 19 is a graph showing the results of the measurements of thespectral reflectance in Example 5-7.

FIG. 20 is a graph showing the results of the measurements of thespectral reflectance in Example 5-8.

FIG. 21 is a graph showing the results of the measurements of thespectral reflectance in Comparative Example 5.

FIG. 22 is a graph showing the results of the measurements of thespectral reflectance in Comparative Examples 6 and 7.

PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

The fluorine-containing polyfunctional (meth)acrylate of the presentinvention is represented by the formula (1) above, wherein when n=1 andm=0, the fluorine-containing polyfunctional (meth)acrylate isrepresented by the formula (1a) below, and when n=0 and m=1, by theformula (1b) below. ##STR3##

Specifically, the present fluorine-containing polyfunctional(meth)acrylate may be a fluorine-containing bifunctional (meth)acrylatehaving (meth)acryloyl groups and a hydroxyl group and represented by theformula (1a) wherein two of Y¹, Y² and Y³ stand for an acryloyl group ora methacryloyl group, and the remaining one of Y¹, Y² and Y³ stands fora hydrogen atom (referred to hereinbelow as diester A); afluorine-containing bifunctional (meth)acrylate having (meth)acryloylgroups and a hydroxyl group and represented by the formula (1b) whereintwo of Y¹, Y² and Y³ stand for an acryloyl group or a methacryloylgroup, and the remaining one of Y¹, Y² and Y³ stands for a hydrogen atom(referred to hereinbelow as diester B); a fluorine-containingtrifunctional (meth)acrylate of the formula (1a) wherein Y¹, Y² and Y³are the same or different groups and stand for an acryloyl group or amethacryloyl group (referred to hereinbelow as triester A); or afluorine-containing trifunctional (meth)acrylate of the formula (1b)wherein Y¹, Y² and Y³ are the same or different groups and stand for anacryloyl group or a methacryloyl group (referred to hereinbelow astriester B). In the formula (1), if X has more than 12 carbon atoms, themanufacture of the fluorine-containing polyfunctional (meth)acrylatebecomes difficult.

Preferred examples of diester A may include

3-perfluorohexyl-2-hydroxypropyl2,2-bis((meth)acryloyloxymethyl)propionate,

3-perfluorohexyl-2-((meth)acryloyloxy)propyl2-((meth)acryloyloxymethyl)-2-(hydroxymethyl)propionate,

3-perfluorooctyl-2-hydroxypropyl2,2-bis((meth)acryloyloxymethyl)propionate, and

3-perfluorooctyl-2-((meth)acryloyloxy)propyl2-((meth)acryloyloxymethyl)-2-(hydroxymethyl)propionate.

Preferred examples of diester B may include

2-perfluorohexyl-(1-hydroxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate,

2-perfluorohexyl-1-((meth)acryloyloxymethyl)ethyl2-((meth)acryloyloxymethyl)-2-(hydroxymethyl)propionate,

2-perfluorooctyl-(1-hydroxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate, and

2-perfluorooctyl-1-((meth)acryloyloxymethyl)ethyl2-((meth)acryloyloxymethyl)-2-(hydroxymethyl)propionate.

Preferred examples of triester A may include

3-perfluorobutyl-2-(meth)acryloyloxypropyl2,2-bis((meth)acryloyloxymethyl)propionate,

3-perfluorohexyl-2-(meth)acryloyloxypropyl2,2-bis((meth)acryloyloxymethyl)propionate,

3-perfluorooctyl-2-(meth)acryloyloxypropyl2,2-bis((meth)acryloyloxymethyl)propionate,

3-perfluorocyclopentylmethyl-2-(meth)acryloyloxypropyl2,2-bis((meth)acryloyloxymethyl)propionate,

3-perfluorocyclohexylmethyl-2-(meth)acryloyloxypropyl2,2-bis((meth)acryloyloxymethyl)propionate, or

3-perfluorocycloheptylmethyl-2-(meth)acryloyloxypropyl2,2-bis((meth)acryloyloxymethyl)propionate.

Preferred examples of triester B may include

2-perfluorobutyl-(1-(meth)acryloyloxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate,

2-perfluorohexyl-(1-(meth)acryloyloxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate,

2-perfluorooctyl-(1-(meth)acryloyloxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate,

2-perfluorocyclopentylmethyl-(1-(meth)acryloyloxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate,

2-perfluorocyclohexylmethyl-(1-(meth)acryloyloxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate, or

2-perfluorocycloheptylmethyl-(1-(meth)acryloyloxymethyl)ethyl2,2-bis((meth)acryloyloxymethyl)propionate.

The above mentioned diester A, diester B, triester A, and triester B maybe used alone or as a mixture as a starting material for a resin withlow refractive index (a mixture of diester A and diester B is referredto as "diester mixture", a mixture of triester A and triester B isreferred to as "triester mixture", and a mixture of diester andtriester, or the diester mixture and the triester mixture arecollectively referred to as "ester mixture" in some cases hereinbelow.

The following two methods may be enumerated as examples of preferablemethods for producing the fluorine-containing polyfunctional(meth)acrylate of the present invention.

The first method includes the steps of (a) reacting carboxylic acidhaving two hydroxymethyl groups represented by the following formula (2)(referred to hereinbelow as "carboxylic acid C") and fluorine-containingdiepoxide represented by the following formula (3) (referred tohereinbelow as "epoxide D") in the presence of a catalyst according toan ordinary ring-opening reaction to obtain a mixture ofhydroxyfluoroalkyl 2,2-bis(hydroxymethyl)carboxylates represented by thefollowing formulae (4) and (5) (both respectively referred tohereinbelow as "ester E"), and (b) esterifying the ester E's with(meth)acryloylchloride, to produce an ester mixture. ##STR4## (in theformulae, X and Z are the same as X and Y in formula (1))

Preferable examples of carboxylic acid C for use in the reaction (a) mayinclude

2,2-bis(hydroxymethyl)acetic acid,

2,2-bis(hydroxymethyl)propionic acid,

2,2-bis(hydroxymethyl)butyric acid, and

2,2-bis(hydroxymethyl)valeric acid. Preferable examples of epoxide D mayinclude

3-trifluoromethyl-1,2-epoxypropane,

3-perfluoroethyl-1,2-epoxypropane,

3-perfluoropropyl-1,2-epoxypropane,

3-perfluorobutyl-1,2-epoxypropane,

3-perfluoropentyl-1,2-epoxypropane,

3-perfluorohexyl-1,2-epoxypropane,

3-perfluoroheptyl-1,2-epoxypropane,

3-perfluorooctyl-1,2-epoxypropane,

3-perfluorononyl-1,2-epoxypropane,

3-perfluorodecyl-1,2-epoxypropane,

3-perfluoroundecyl-1,2-epoxypropane,

3-perfluorododecyl-1,2-epoxypropane,

3-perfluorotridecyl-1,2-epoxypropane,

3-(perfluoro-1-methylethyl)-1,2-epoxypropane,

3-(perfluoro-2-methylpropyl)-1,2-epoxypropane,

3-(perfluoro-3-methylbutyl)-1,2-epoxypropane,

3-(perfluoro-4-methylpentyl)-1,2-epoxypropane,

3-(perfluoro-5-methylhexyl)-1,2-epoxypropane,

3-(perfluoro-6-methylheptyl)-1,2-epoxypropane,

3-(perfluoro-7-methyloctyl)-1,2-epoxypropane,

3-(perfluoro-8-methylnonyl)-1,2-epoxypropane,

3-(perfluoro-9-methyldecyl)-1,2-epoxypropane,3-(perfluoro-10-methylundecyl)-1,2-epoxypropane,3-(perfluoro-11-methyldodecyl)-1,2-epoxypropane, and3-(perfluoro-12-methyltridecyl)-1,2-epoxypropane.

For reacting carboxylic acid C and epoxide D in reaction (a), it ispreferred to charge 0.8 to 5 mol, more preferably 1.0 to 1.8 mol ofcarboxylic acid C per 1 mol of epoxide D.

Examples of the catalyst used in reaction (a) may include tertiaryamines such as triethylamine or benzyldimethylamine; or quaternaryammonium salts such as tetraethylammonium bromide or tetramethylammoniumbromide. The amount of the catalyst is preferably 0.001 to 5% by weight,more preferably 0.01 to 2.5% by weight of the total weight of thereaction mixture.

The temperature for the reaction (a) is preferably 40 to 200° C., morepreferably 80 to 120° C. The duration of the reaction is preferably 1 to48 hours, more preferably 2 to 12 hours.

The mixture of ester E's obtained by the reaction (a) may be, before itis subjected to step (b), dissolved in an organic solvent such aschloroform, methylene chloride, trifluoromethylbenzene, ethyl acetate ormixtures thereof, and washed with an alkaline aqueous solution such assodium hydroxide or sodium carbonate, for removing the catalyst,depending on the need. The mixture of ester E's may be purified byvacuum distillation, recrystallization, or column chromatography.

For reacting ester E and (meth)acryloylchloride in reaction (b) toproduce a diester mixture, it is preferred to charge 1.6 to 10 mol, morepreferably 2.0 to 4.0 mol of (meth)acryloylchloride per 1 mol of esterE. On the other hand, to produce a triester mixture, it is preferred tocharge 2.4 to 15 mol, more preferably 3.0 to 6.0 mol of(meth)acryloylchloride per 1 mol of ester E.

In reaction (b), base such as tertiary alkylamine, for example,triethylamine or benzyldimethylamine, or pyridine may be added to thereaction mixture for capturing hydrochloric acid generated during thereaction. The amount of base is preferably 1.6 to 10.0 mol, morepreferably 2.0 to 4.5 mol per 1 mol of ester E, for producing a diestermixture. On the other hand, for producing triester mixture, the amountof base is preferably 2.4 to 15.0 mol, more preferably 3.0 to 7.0 per 1mol of ester E.

It is preferred to proceed with reaction (b) in a suitable solvent.Examples of such a solvent may include chloroform, methylene chloride,trifluoromethylbenzene, or mixtures thereof. The amount of the solventis preferably 20 to 2000 parts by weight, more preferably 100 to 500parts by weight based on 100 parts by weight of the total amount ofester E, (meth)acryloylchloride, and the base.

The temperature for reaction (b) is preferably -60 to 20° C., morepreferably -40 to 0° C., and the duration of reaction (b) is preferably0.1 to 12 hours, more preferably 0.5 to 2 hours.

After the completion of reaction (b), the resulting system including thegenerated ester mixture may be subjected to a variety of treatmentsdepending on the need. For example, a small amount of alcohols such asmethanol or ethanol, or water may be added to the reaction system fordecomposing the excess (meth)acryloylchloride in the reaction system.The reaction system may also be washed with an acid aqueous solutionsuch as diluted hydrochloric acid. The reaction system may also besubjected to purification such as vacuum distillation, recrystallizationor column chromatography. In the vacuum distillation, it is preferred toadd a polymerization inhibitor such as hydroquinone, hydroquinonemonoethyl ether, or tert-butylcatechol to the system for inhibitingpolymerization. The amount of the polymerization inhibitor is preferably0.001 to 2% by weight, more preferably 0.005 to 0.2% by weight of thetotal weight of the mixture resulting from the reaction (c).

The diester mixture generated by the reaction (b) is usually a mixtureof four structural isomers composed of two sorts of diester A and twosorts of diester B. Specifically, the isomers are diester A¹ representedby the formula (6), diester A² represented by the formula (7), diesterB¹ represented by the formula (8), and diester B² represented by theformula (9): ##STR5## (in the formulae, X, Y¹, Y², Y³ and Z are the sameas X, Y¹, Y², Y³ and Z in the formula (1))

The objective compound may be obtained by separation and isolation ofdiester A¹, diester A², diester B¹ or diester B², or diester Aconsisting of diester A¹ and diester A², or diester B consisting ofdiester B¹ and diester B². On the other hand, the resulting triestermixture is a mixture of structural isomers triester A and triester B.Thus, in the same manner as for diester A and diester B, the objectivecompound may be obtained by separating and isolating the triester A andtriester B from the triester mixture. In either case, the separating andisolating methods may include, for example, liquid chromatography forseparation.

The second method includes the steps of (c) producing2,2-bis((meth)acryloyloxymethyl)carboxylic acid represented. by thefollowing formula (10) (referred to hereinbelow as carboxylic acid F)from the aforementioned carboxylic acid C by a method, for example, asdescribed in Japanese Laid-open Patent Application No.63-99038, that is,by reacting the aforementioned carboxylic acid C with (meth)acrylicacid, (meth)acryloylchloride or (meth)acrylate in the presence of, ifneeded, any suitable catalyst ##STR6## (in the formula, Y¹, Y² and Z arethe same as Y¹, Y² and Z in the formula (1)), and

(d) reacting the carboxylic acid F with the aforementioned epoxide D inthe presence of a catalyst according to an ordinary ring-openingreaction, to obtain an ester mixture. The resulting ester mixture is amixture of diester A¹ represented by the formula (6) and diester B¹represented by the formula (8).

For reacting carboxylic acid C and (meth)acryloylchloride in reaction(c), it is preferred to charge 1.6 to 10 mol, more preferably 2.0 to 4.0mol of (meth)acryloylchloride per 1 mol of carboxylic acid C.

In reaction (c), base such as tertiary alkylamine, for example,triethylamine or benzyldimethylamine, or pyridine may be added to thereaction system for capturing the hydrochloric acid generated during thereaction. The amount of base is preferably 1.6 to 10 mol, morepreferably 2.0 to 4.5 mol per 1 mol of carboxylic acid C.

It is preferred to proceed with reaction (c) in a suitable solvent.Examples of such a solvent may include chloroform, methylene chloride,trifluoromethylbenzene, and the like. The amount of the solvent ispreferably 20 to 2000 parts by weight, more preferably 100 to 500 partsby weight based on 100 parts by weight of the total amount of carboxylicacid C, (meth)acryloylchloride, and the base.

The temperature for reaction (c) is preferably -60 to 20° C., morepreferably -40 to 0° C., and the duration of reaction (c) is preferably0.1 to 12 hours, more preferably 0.5 to 2 hours.

Carboxylic acid F produced by the reaction (c) may be subjected to avariety of treatments depending on the need, before subsequent treatment(d). For example, a small amount of alcohols such as methanol or ethanolor water may be added to the reaction system for decomposing the excess(meth)acryloylchloride in the reaction system. Carboxylic acid F mayalso be washed with an acid aqueous solution such as dilutedhydrochloric acid. Carboxylic acid F may also be purified by vacuumdistillation, recrystallization or column chromatography. In the vacuumdistillation, it is preferred to add a polymerization inhibitor such ashydroquinone, hydroquinone monoethyl ether, or tert-butylcatechol to thesystem for inhibiting polymerization. The amount of the polymerizationinhibitor is preferably 0.001 to 2.0% by weight, more preferably 0.005to 0.2% by weight of the total weight of the mixture after the reaction.

For reacting the epoxide D and carboxylic acid F in the reaction (d),the mixing ratio of carboxylic acid F is preferably 0.8 to 5 mol, morepreferably 1.0 to 1.8 mol per 1 mol of epoxide D.

Examples of the catalyst used in reaction (d) may include publicly knowncatalysts such as tertiary amines including triethylamine orbenzyldimethylamine; or quaternary ammonium salts includingtetraethylammonium bromide or tetramethylammonium bromide. The amount ofthe catalyst is preferably 0.001 to 5.0% by weight, more preferably 0.01to 2.5% by weight of the total weight of the reaction mixture.

In the reaction (d), it is preferred to add a polymerization inhibitorto the reaction system. Preferable polymerization inhibitors may includehydroquinone, hydroquinone monoethyl ether, or tert-butylcatechol. Theamount of the polymerization inhibitor is preferably 0.001 to 2% byweight, more preferably 0.005 to 0.2% by weight of the total weight ofthe reaction mixture.

The temperature for the reaction (d) is preferably 40 to 200° C., morepreferably 80 to 120° C. The duration of the reaction (d) is preferably1 to 48 hours, more preferably 2 to 12 hours.

After the completion of reaction (d), the resulting mixture containingthe generated diester mixture may be subjected to a variety oftreatments depending on the need before use. For example, the mixturemay be dissolved in an organic solvent such as chloroform, methylenechloride or trifluoromethylbenzene, and then washed with an alkalineaqueous solution such as sodium hydroxide or sodium carbonate, forremoving the catalyst. The mixture may be purified by vacuumdistillation, recrystallization, column chromatography, and the like,depending on the need. In the vacuum distillation, it is preferred toadd a polymerization inhibitor such as hydroquinone, hydroquinonemonoethyl ether, or tert-butylcatechol to the mixture for inhibitingpolymerization. The amount of the polymerization inhibitor is preferably0.001 to 2% by weight, more preferably 0.005 to 0.2% by weight of thetotal weight of the mixture resulting from the reaction.

On the other hand, a triester mixture may be produced by (e) esterifyingthe diester mixture obtained by the reactions (c) and (d) with oneequivalent of additional (meth)acryloylchloride.

For reacting the diester mixture and (meth)acryloylchloride in reaction(e), it is preferred to charge 0.8 to 5 mol, more preferably 1.0 to 2.0mol of (meth)acryloylchloride per 1 mol of the diester mixture.

In reaction (e), base such as tertiary alkylamine, for example,triethylamine or benzyldimethylamine, or pyridine may be added to thereaction system for capturing hydrochloric acid generated during thereaction. The amount of base is preferably 0.8 to 5.0 mol, morepreferably 1.0 to 2.5 mol per 1 mol of the diester mixture.

It is preferred to proceed with reaction (e) in a suitable solvent.Examples of such a solvent may include chloroform, methylene chloride,trifluoromethylbenzene, and the like. The amount of the solvent ispreferably 20 to 2000 parts by weight, more preferably 100 to 500 partsby weight based on 100 parts by weight of the total amount of thediester mixture, (meth)acryloylchloride, and the base.

The temperature for reaction (e) is preferably -60 to 20° C., morepreferably -40 to 0° C., and the duration of reaction (e) is preferably0.1 to 12 hours, more preferably 0.5 to 2 hours.

After the completion of reaction (e), the resulting system containinggenerated ester mixture may be subjected to a variety of treatmentsdepending on the need. For example, a small amount of alcohols such asmethanol or ethanol, or water may be added to the reaction system fordecomposing the excess (meth)acryloylchloride in the reaction system.The reaction system may also be washed with an acid aqueous solutionsuch as diluted hydrochloric acid. The reaction system may also besubjected to purification such as vacuum distillation, recrystallizationor column chromatography. In the vacuum distillation, it is preferred toadd a polymerization inhibitor such as hydroquinone, hydroquinonemonoethyl ether, or tert-butylcatechol to the system for inhibitingpolymerization. The amount of the polymerization inhibitor is preferably0.001 to 2% by weight, more preferably 0.005 to 0.2% by weight of thetotal weight of the mixture resulting from the reaction (e).

The triester mixture generated by the reaction (e) is a mixture ofstructural isomers triester A and triester B. The objective compound maybe obtained by separation and isolation of triester A and triester B.The separation and isolation may be performed, for example, by liquidchromatography for separation.

The fluorine-containing polyfunctional (meth)acrylate itself of thepresent invention may be cured by cross-linking to produce a cured filmhaving excellent abrasion resistance and adhesion, and may be used aloneor as a mixture.

The composition of the present invention contains thefluorine-containing polyfunctional(meth)acrylate, or both thefluorine-containing polyfunctional (meth)acrylate and powders of aninorganic compound. The fluorine-containing polyfunctional(meth)acrylate is a compound represented by the formula (1), and mayspecifically be a fluorine-containing polyfunctional (meth)acrylateselected from the group consisting of the aforementioned diester A¹,diester A², diester B¹, diester B², triester A, triester B and mixturesthereof (sometimes collectively referred to as polyfunctional ester Ahereinbelow). As the mixture, various ester mixtures obtained during theaforementioned method of producing the polyfunctional ester A may bedirectly used.

The content of polyfunctional ester A is 5 to 100% by weight, preferably10 to 100% by weight of the total weight of the composition. On theother hand, the content of the powders of the inorganic compound ispreferably less than 90% by weight of the total weight of thecomposition. When the composition is cured by polymerization, it iscross-linked to acquire three-dimensional net work structure, therebygiving a cured film having excellent abrasion resistance, adhesion, wearresistance, heat resistance, and weatherability.

There is no particular limitation to the powders of the inorganiccompound, but it is preferably a compound having the refractive index of1.5 or lower. Specifically, powders of magnesium fluoride (refractiveindex 1.38), silicon oxide (refractive index 1.46), aluminum fluoride(refractive index 1.33 to 1.39), calcium fluoride (refractive index1.44), lithium fluoride (refractive index 1.36 to 1.37), sodium fluoride(refractive index 1.32 to 1.34), or thorium fluoride (refractive index1.45 to 1.50) are preferable. The particle size of the powders ispreferably sufficiently smaller than the wave length of the visibleradiation for the purpose of ensuring the transparency of the lowrefractivity material. Specifically, the particle size is preferably notlarger than 100 nm, more preferably not larger than 50 nm.

The inorganic powders is used preferably in the form of an organic solin which the powders are previously dispersed in an organic dispersionmedium, for preventing the decreasing of dispersion stability in thecomposition and of adhesion in the low refractivity material. Further,for increasing the dispersion stability in the composition and adhesionin the low refractivity material, the surface of the inorganic powdercomposition may be modified with various coupling agents. The variouscoupling agents may include, for example, silicide substituted byorganic residues; alkoxides of metals such as aluminum, titanium,zirconium, antimony, or mixtures thereof; salts of organic acids; andcoordination compounds combined with compounds which can be coordinated.

The composition of the present invention may optionally containpreferably less than 95% by weight, more preferably less than 90% byweight other curing materials such as ordinary thermosetting monomers orenergy-beam curable monomers. Preferred examples of the thermosettingmonomers and energy-beam curable monomers may include polyfunctionalmonomers having two or more polymerizable unsaturated groups, forexample, polyalkylene glycol di(meth)acrylate such as dipentaerythritolhexa(meth)acrylate, dipentaerythritol penta(meth)acrylate,dipentaerythritol tetra(meth)acrylate, pentaerythritoltetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoldi(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate,ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropanedi(meth)acrylate, trimethylolpropane tri(meth)acrylate,trimethylolpropane di(meth)acrylate, tetramethylolmethane tetraacrylate,1,1,1-tris(acryloyloxyethoxyethoxy)propane,2,2-bis(4-acryloyloxyethoxyethoxyphenyl)propane,2,2-bis(4-acryloyloxyethoxyethoxycyclohexyl)propane,2,2-bis(4-acryloyloxyethoxyethoxyphenyl)methane, neopentyl glycoldi(meth)acrylate, hydrogenated dicyclopentadienyl di(meth)acrylate,tris(hydroxyethyl)isocyanurate triacrylate,tris(hydroxyethyl)isocyanurate diacrylate, 1,4-butanedioldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, isobornyldi(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropyleneglycol di(meth)acrylate, or polytetramethylene glycol di(meth)acrylate.These may be used alone or as a mixture.

The composition of the present invention may optionally containmonofunctional (meth)acrylate as long as the desired effect of thepresent invention is not deteriorated. Such monofunctional(meth)acrylate may preferably be fluorine-containing monofunctional(meth)acrylate in view of the purpose of lowering the refractive indexof the monomer composition, such as 2,2,2-trifluoroethyl(meth)acrylate,2,2,3,3,3-pentafluoropropyl(meth)acrylate,2,2,3,3,4,4,4-heptafluorobutyl(meth)acrylate,2,2,3,3,4,4,5,5,5-nonafluoropentyl(meth)acrylate,2,2,3,3,4,4,5,5,6,6,6-undecafluorohexyl(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoroheptyl(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl(meth)acrylate,3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-nonadecafluorodecyl(meth)acrylate,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl(meth)acrylate, 2-trifluoromethyl-3,3,3-trifluoropropyl(meth)acrylate,3-trifluoromethyl-4,4,4-trifluorobutyl(meth)acrylate,1-methyl-2,2,3,3,3-pentafluoropropyl(meth)acrylate, or1-methyl-2,2,3,3,4,4,4-heptafluorobutyl(meth)acrylate. These may be usedalone or as a mixture.

The composition of the present invention may also contain, if necessary,fluorine-containing bifunctional (meth)acrylate other than the diestermixture as a curing material as long as the desired effect of thepresent invention is not deteriorated. Preferred examples of thefluorine-containing bifunctional (meth)acrylate other than the diestermixtures may include 2,2,2-trifluoroethylethylene glycoldi(meth)acrylate, 2,2,3,3,3-pentafluoropropylethylene glycoldi(meth)acrylate, 2,2,3,3,4,4,4-heptafluorobutylethylene glycoldi(meth)acrylate, 2,2,3,3,4,4,5,5,5-nonafluoropentylethylene glycoldi(meth)acrylate, 2,2,3,3,4,4,5,5,6,6,6-undecafluorohexylethylene glycoldi(meth)acrylate, 2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoroheptylethyleneglycol di(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctylethylene glycoldi(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-nonadecafluorodecylethyleneglycol di(meth)acrylate, 2,2,3,3-tetrafluorobutanediol di(meth)acrylate,2,2,3,3,4,4-hexafluoropentadiol di(meth)acrylate,2,2,3,3,4,4,5,5-octafluorohexanediol di(meth)acrylate,2,2,3,3,4,4,5,5,6,6-decafluoroheptanediol di(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7-dodecafluorooctanediol di(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,8,8-tetradecafluorononanediol di(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorodecanedioldi(meth)acrylate,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10-octadecafluoroundecanedioldi(meth)acrylate, or2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11-eicosafluorododecanedioldi(meth)acrylate. These may be used alone or as a mixture.

The composition of the present invention may optionally be mixed with apolymer for improving the film forming property. The polymer to be addedis not particularly limited, but preferably a polymer offluorine-containing (meth)acrylate, or a copolymer offluorine-containing (meth)acrylate with other monomers. The mixing ratioof the polymer is preferably 25 parts by weight or less, more preferably10 parts by weight or less based on 100 parts by weight of the curingmaterials in the monomer composition.

The low refractivity material of the present invention is prepared bycuring the above-mentioned composition by polymerization, and has therefractive index of 1.49 or lower, more preferably 1.35 to 1.49.

The curing by polymerization may be carried out by optionally admixing acuring initiator and/or a solvent such as isopropylalcohol or toluene tothe monomer composition; applying the resulting mixture to a substratesuch as a transparent substrate by an ordinary coating method such asroll coating method, gravure coating method, dip coating method, or spincoating method; drying; and curing by heating or irradiation with activeenergy beam such as ultraviolet ray, electron beam, or radio active ray.The conditions for curing by polymerization may suitably be selecteddepending on the curing materials in the composition. When the lowrefractivity material is formed into a film, the film thickness maysuitably be selected depending on the purpose.

Examples of the curing initiator may include azo radical polymerizationinitiators such as azobisisobutyronitrile,azobiscyclohexanecarbonitrile, or azobisvaleronitrile; radicalpolymerization initiators of organic peroxide type such as benzoylperoxide, tert-butylhydroperoxide, cumene peroxide, or diacylperoxide;or photopolymerization initiators such as benzoin compounds includingbenzoin, benzoin methyl ether, benzoin ethyl ether, or benzoin isopropylether, carbonyl compounds including benzyl, benzophenone, acetophenone,or Michler's ketone, azo compounds including azobisisobutyronitrile orazodibenzoyl, or a mixture of α-diketone and a tertiary amine. Theamount of the curing initiator may be 0.01 to 10% by weight of the totalweight of the curing materials in the monomer composition and the curinginitiator.

The reflection reducing film of the present invention has a transparentsubstrate and a layer of the low refractivity material. The layer of thelow refractivity material preferably has a suitable thickness. Thesuitable thickness is preferably selected so that the wave length whichindicated the minimum reflectance of the reflection reducing film isusually 420 to 720 nm, more preferably 520 to 620 nm.

The kind of the transparent substrate is not particularly limited aslong as the substrate is transparent. Usually, a PET (polyethyleneterephthalate) film, a TAC (triacetyl cellulose) film, an acryl film, ora polycarbonate film may be used.

The reflection reducing film of the present invention may be composed ofthe transparent substrate and the layer of the low refractivity materialthereon, or of the transparent substrate, the layer of the lowrefractivity material, and at least one material layer therebetween. Thematerial layer may be a layer of a high refractivity material forimproving the reflection reducing effect. The layer of the highrefractivity material preferably has the refractive index of 1.55 orhigher, and the thickness of the layer may preferably be selected sothat the wave length which indicated the maximum reflectance of the filmprovided with the layer of the high refractivity material is usually 400to 900 nm.

The transparent substrate may be provided with one layer of the lowrefractivity material and one layer of the high refractivity material,or it may be provided with two or more layers of each material. When twoor more layers of each material are provided, the layers of the lowrefractivity material and the high refractivity material may belaminated alternately, with the outermost layer being of the lowrefractivity material. When two or more layers of each material areprovided, each layer of the low refractivity material or the highrefractivity material may be made of the same or different materials.

The layer of the low refractivity material may be formed by optionallyadmixing a curing initiator and/or a solvent such as isopropylalcohol ortoluene to the fluorine-containing composition; applying the resultingmixture to a substrate such as a transparent substrate by an ordinarycoating method such as roll coating method, gravure coating method, dipcoating method, or spin coating method; drying; and curing by heating orirradiation with active energy beam such as ultraviolet ray, electronbeam, or radio active ray. The conditions for curing by polymerizationmay suitably be selected depending on the curing materials in thecomposition. The layer of the high refractivity material may be formedin the same way.

The reflection reducing film of the present invention may be providedwith a hard coating for further improving the abrasion resistance of thereflection reducing film. The hard coating may be provided between thelaminated layers of the low refractivity material and the highrefractivity material and the transparent substrate. The kind of thehard coating is not particularly limited, and may be made of an ordinaryresin for hard coating prepared from the polyfunctional monomer havingtwo or more polymerizable unsaturated groups. However, if the differencein the refractive index of the transparent substrate and the hardcoating is too large, reflection will occur at the interfacetherebetween. Thus, the difference in the refractive index of thetransparent substrate and the hard coating is preferably kept as smallas possible. The thickness of the hard coating is preferably 1 to 10 μm,more preferably 3 to 5 μm. The method of forming the hard coating is notparticularly limited, and may include applying the hard coating materialto a substrate such as a transparent substrate by an ordinary coatingmethod such as roll coating method, gravure coating method, dip coatingmethod, or spin coating method; drying; and curing by an ordinary methodusing energy beam or heat.

Since the fluorine-containing polyfunctional (meth)acrylate of thepreset invention has a plurality of (meth)acryloyl groups, it is curedby cross-linking polymerization to acquire three-dimensional net workstructure, and gives a cured film having high surface hardness andexcellent abrasion resistance, wear resistance, heat resistance, andweatherability. Further, the diester mixture having a hydroxyl group canimprove the adhesion of the cured coating film. The obtained curedproduct has superior light transmittance and low refractive index aswell as excellent adhesion, so that it is useful as a resin with lowrefractive index for antireflection films or clad materials for opticalfibers which are required to have superior abrasion resistance andadhesion.

Since the composition of the present invention contains the particularfluorine-containing polyfunctional (meth)acrylate, the cured productprepared by polymerizing the composition has the properties of both thelow refractive index and the hardness of (meth)acrylate, and thecomposition can be formed into a film by applying on a substrate andcured by polymerization, thereby preparing the low refractivity materialof the present invention. The low refractivity material of the presentinvention has the properties of both the low refractive index and thehardness of (meth)acrylate, and has low refractive index and highsurface hardness. Further, by using the diester mixture having ahydroxyl group, its adhesion to other materials is further improved. Thecomposition of the present invention may further contain powders of aninorganic compound, in addition to the particular fluorine-containingpolyfunctional (meth)acrylate. By admixing the inorganic compound,abrasion resistance of the obtained low refractivity material mayfurther be increased.

The reflection reducing film of the present invention is provided with alayer of the low refractivity material, it has low refractive index,high surface hardness, and high adhesion, and may be applied to avariety of usage. Accordingly, by using the composition of the presentinvention, reflection reducing films having a layer of the lowrefractivity material with larger area may be produced continuously andeffectively at a low cost, compared to the conventional vapor depositionof magnesium fluoride.

EXAMPLES

The present invention will now be explained with reference to Examplesand Comparative Examples, but the present invention is not limitedthereto.

Example 1-1

Into a reactor equipped with a stirrer, a cooling tube and a gasintroducing tube, 476 g (1.0 mol) of 3-perfluorooctyl-1,2-epoxypropane,161 g (1.5 mol) of 2-bis(hydroxymethyl)propionic acid, 6.4 g oftetraethylammonium bromide, and 600 ml of isopropylalcohol were charged,gradually heated up to 95 to 100° C. in an oil bath, stirred at thistemperature for 4 hours, and then cooled down to the room temperature.To the resulting reaction liquid was added 5 liters of water forprecipitating a paste. The precipitate is separated by filtration andthen dissolved in 1000 ml of ethyl acetate, and the solution thusobtained was washed three times with 1000 ml of water. The solvent wasremoved from the washed solution under reduced pressure to obtain whitecrystals. The crystals are believed to be a mixture of compounds havingstructures represented by the following formulae (11) and (12). ##STR7##

Into a reactor equipped with a stirrer, a thermometer, a gas introducingtube and a dropping funnel, the white crystals obtained by the abovereaction, 303.6 g of triethylamine, and 1000 ml of chloroform werecharged. Under ice cooling, 271.5 g (3.0 mol) of acryloylchloride weredissolved in 300 ml of chloroform, and the resulting solution was addeddropwise to the reaction liquid from the dropping funnel while thetemperature of the reaction liquid was kept below 5° C. After thecompletion of dropping, the reaction liquid was kept under ice coolingand stirred for two hours. Chloroform was then removed from the reactionliquid under reduced pressure, and the resulting yellow crystals werefurther purified by column chromatography using an ethylacetate/n-hexane mixed solvent (1:4 by volume) as a developing solventfollowed by removal of the solvent under reduced pressure, therebyobtaining 215 g of white crystal product G (yield 30%).

A portion of product G was further separated by high speed liquidchromatography. Separation was performed employing TSK gel Silica-60(internal diameter of 21.5 mm: length of 300 mm: manufactured by TOSOHCORP.) as a column, and a mixed solvent of ethyl acetate/n-hexane(volume ratio 1:5), at flow rate of 5 ml per minute. For detection, anultraviolet detector was employed at the wave length of 230 nm. As theresult of analysis, the obtained compounds G-1, G-2, G-3 and G-4 werethe compounds having the structures represented by the followingformulae (13), (14), (15) and (16), respectively. The results of ¹H-NMR, ¹⁹ F-NMR, and Exact MS of these compounds thus obtained are shownbelow together with the structural formulae thereof. ##STR8##

(Analytical results of G-1).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.43(dd,2H); 6.11(dd,1H); 6.11(dd,1H);5.88(dd,2H); 4.53-4.31(m,1H); 4.43,4.36(ABq,2H); 4.41,4.39(ABq,2H);4.28,4.12(dABq,2H); 2.49-2.20(m,2H); 1.33(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.47;-119.72;-118.91; -118.60;-109.76; -77.79.

Exact MS: Measured value; 718.0865, Theoretical value;C₂₂ H₁₉ F₁₇ O₇:718.0859. ##STR9##

(Analytical results of G-2).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,1H); 6.42(dd,1H); 6.12(dd,1H);6.11(dd,1H); 5.89(dd,1H); 5.88(dd,1H); 5.38-5.35(m,1H);4.43,4.34(ABq,2H); 4.28,4.12(dABq,2H); 3.90,3.74(ABq,2H);2.49-2.21(m,2H); 1.33(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.11;-120.47;-119.72;-118.92; -118.60;-109.76; -77.79.

Exact MS: Measured value; 718.0862, Theoretical value; C₂₂ H₁₉ F₁₇ O₇ :718.0859. ##STR10##

(Analytical results of G-3).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.42(dd,2H); 6.11(dd,1H); 6.11(dd,1H);5.88(dd,2H); 5.38-5.34(m,1H); 4.43,4.36(ABq,2H); 4.41,4.39(ABq,2H);3.89,3.75(dABq,2H); 2.49-2.20(m,2H); 1.32(s,3H).

¹⁹ F-NMR (δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.47;-119.71;-118.91; -118.60;-109.76; -77.78.

Exact MS: Measured value; 718.0862, Theoretical value; C₂₂ H₁₉ F₁₇ O₇:718.0859. ##STR11##

(Analytical results of G-4).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,1H); 6.42(dd,1H); 6.12(dd,1H);6.11(dd,1H); 5.89(dd,1H); 5.88(dd,1H); 5.39-5.34(m,1H);4.43,4.36(ABq,2H); 4.29,4.13(dABq,2H); 3.90,3.75(ABq,2H);2.49-2.20(m,2H); 1.33(s,3H).

¹⁹ F-NMR (δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.46;-119.72;-118.91; -118.61;-109.76; -77.79.

Exact MS: Measured value; 718.0856, Theoretical value; C₂₂ H₁₉ F₁₇ O₇ :718.0859.

Example 1-2

198 g of white crystal product H (yield 32%) was obtained in the sameway as in Example 1-1 via the compounds of the structures represented bythe formulae (17) and (18), except that 376.1 g (1.0 mol) of3-perfluorohexyl-1,2-epoxypropane was employed instead of3-perfluorooctyl-1,2-epoxypropane. ##STR12##

A portion of product H was separated by high speed liquid chromatographyin the same way as in Example 1-1. The obtained compounds H-1, H-2, H-3and H-4 were the compounds having the structures represented by thefollowing formulae (19), (20), (21) and (22), respectively. The resultsof ¹ H-NMR, ¹⁹ F-NMR, and Exact MS of these compounds thus obtained areshown below together with the structural formulae thereof. ##STR13##

(Analytical results of H-1).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.43(dd,2H); 6.12(dd,1H); 6.11(dd,1H);5.88(dd,2H); 4.53-4.31(m,1H); 4.43,4.37(ABq,2H); 4.41,4.39(ABq,2H);4.28,4.12(dABq,2H); 2.49-2.21(m,2H); 1.34(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.09;-120.39;-119.89;-118.89; -109.39;-77.90.

Exact MS: Measured value; 618.0931, Theoretical value; C₂₀ H₁₉ F₁₃ O₇ :618.0923. ##STR14##

(Analytical results of H-2).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,1H); 6.42(dd,1H); 6.11(dd,1H);6.10(dd,1H); 5.88(dd,1H); 5.88(dd,1H); 5.38-5.35(m,1H);4.43,4.34(ABq,2H); 4.28,4.12(dABq,2H); 3.90,3.75(ABq,2H);2.49-2.21(m,2H); 1.32(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.09;-120.39;-119.88;-118.89; -109.38;-77.90.

Exact MS: Measured value; 618.0921, Theoretical value; C₂₀ H₁₉ F₁₃ O₇ :618.0923. ##STR15##

(Analytical results of H-3).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.42(dd,2H); 6.11(dd,1H); 6.11(dd,1H);5.87(dd,2H); 5.37-5.34(m,1H); 4.43,4.36(ABq,2H); 4.41,4.40(ABq,2H);3.89,3.75(dABq,2H); 2.49˜2.20(m,2H); 1.33(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.08;-120.39;-119.88;-118.89; -109.39;-77.90.

Exact MS: Measured value; 618.0919, Theoretical value; C₂₀ H₁₉ F₁₃ O₇ :618.0923. ##STR16##

(Analytical results of H-4).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,1H); 6.42(dd,1H); 6.12(dd,1H);6.11(dd,1H); 5.89(dd,1H); 5.87(dd,1H); 5.38-5.33(m,1H);4.43,4.36(ABq,2H); 4.30,4.14(dABq,2H); 3.90,3.75(ABq,2H);2.49-2.21(m,2H); 1.33(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.09;-120.39;-119.88;-118.88; -109.39;-77.89.

Exact MS: Measured value; 618.0929, Theoretical value; C₂₀ H₁₉ F₁₃ O₇ :618.0923.

Example 1-3

Into a reactor equipped with a stirrer, a thermometer a gas introducingtube and a dropping funnel, 201 g (1.5 mol) of2,2-bis(hydroxymethyl)propionic acid, 304 g (3.0 mol) of trimethylamineand 600 ml of chloroform were charged. Under ice cooling, 406 g (4.5mol) of acryloylchloride were dissolved in 400 ml of chloroform, and theresulting solution was added dropwise to the reaction liquid from thedropping funnel while the temperature of the reaction liquid was keptbelow 5° C. After the completion of dropping, the reaction liquid waskept under ice cooling and stirred for two hours. Chloroform was thenremoved from the reaction liquid under reduced pressure. Resultingyellow crystals were purified by column chromatography using as adeveloping solvent ethyl acetate/n-hexane mixed solvent (1:4 by volume).The solvent was then removed under reduced pressure to obtain2,2-bis(acryloyloxymethyl)propionic acid as white crystals. ##STR17##

Into a reactor equipped with a stirrer, a cooling tube and a gasintroducing tube, 290 g (1.2 mol) of 2,2-bis(acryloyloxymethyl)propionicacid obtained by the above reaction, 476 g (1.0 mol) of3-perfluorooctyl-1,2-epoxypropane, 161 g (1.2 mol) of2-bis(hydroxymethyl)propionic acid, 6.4 g of tetraethylammonium bromide,and 600 ml of isopropylalcohol were charged, and gradually heated up to95 to 100° C. in an oil bath, stirred at this temperature for 4 hours,and then cooled down to the room temperature. To the resulting reactionliquid was added 5 liters of water for precipitating a paste. Theprecipitate was separated by filtration and then dissolved in 1000 ml ofethyl acetate, and the solution thus obtained was washed three timeswith 1000 ml of water. The solvent was removed from the washed solutionunder reduced pressure to obtain white crystal product I.

A portion of product I was further separated by high speed liquidchromatography in the same way as in Example 1-1. The obtained compoundsI-1 and I-2 were the compounds having the structures represented by theabove formulae (13) and (15), respectively. The results of ¹ H-NMR, ¹⁹F-NMR, and Exact MS of the obtained compounds are shown below.

(Analytical results of I-1).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,2H); 6.11(dd,1H); 6.11(dd,1H);5.88(dd,2H); 4.54-4.31(m,1H); 4.43,4.36(ABq,2H); 4.41,4.39(ABq,2H);4.28,4.12(dABq,2H); 2.49-2.20(m,2H); 1.34(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.46;-119.72;-118.91; -118.60;-109.76; -77.78.

Exact MS: Measured value; 718.0856, Theoretical value; C₂₂ H₁₉ F17O₇:718.0859.

(Analytical results of I-2).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.42(dd,2H); 6.11(dd,1H); 6.11(dd,1H);5.88(dd,2H); 5.37-5.34(m,1H); 4.43,4.36(ABq,2H); 4.41,4.38(ABq,2H);3.89,3.75(dABq,2H); 2.48-2.20(m,2H); 1.32(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.47;-119.72;-118.91; -118.60;-109.76; -77.79.

Exact MS: Measured value; 718.0852, Theoretical value; C₂₂ H₁₉ F₁₇ O₇ :718.0859.

Example 2-1

Into a reactor equipped with a stirrer, a cooling tube, and a gasintroducing tube, 476 g (1.0 mol) of 3-perfluorooctyl-1,2-epoxypropane,161 g (1.2 mol) of 2,2-bis(hydroxymethyl)propionic acid, 6.4 g oftetraethylammonium bromide and 600 ml of isopropylalcohol were charged,gradually heated up to 95 to 100° C. in an oil bath, stirred at thistemperature for 4 hours, and then cooled down to the room temperature.To the resulting reaction liquid was added 5 liters of water forprecipitating a paste. The precipitate was separated by filtration andthen dissolved in 1000 ml of ethyl acetate, and the solution thusobtained was washed three times with 1000 ml of water. The solvent wasremoved from the washed solution under reduced pressure to obtain whitecrystals. These white crystals are believed to be a mixture of compoundshaving structures represented by the above formulae (11) and (12).

Into a reactor equipped with a stirrer, a thermometer, a gas introducingtube and a dropping funnel, 535 g of the white crystals obtained by theabove reaction, 455.4 g of triethylamine, 1000 ml of chloroform werecharged. Under ice cooling, 479.6 g (4.5 mol) of acryloylchloride weredissolved in 450 ml of chloroform, and the resulting solution was addeddropwise to the reaction liquid from the dropping funnel while thetemperature of the reaction liquid was kept below 5° C. After thecompletion of dropping, the reaction liquid was kept under ice coolingand stirred for two hours. Chloroform was then removed from the reactionliquid under reduced pressure, and the obtained yellow crystals werefurther purified by column chromatography using as a developing solventethyl acetate/n-hexane mixed solvent (1:4 by volume). The solvent wasthen removed under reduced pressure to obtain 232 g of the objectivewhite crystal product J (yield 30%).

A portion of product J was further separated by high speed liquidchromatography in the same way as in Example 1-1. The compounds J-1 andJ-2 obtained as the result of the separation were the compounds havingthe structures represented by the following formulae (24) and (25),respectively. The results of ¹ H-NMR, ¹⁹ F-NMR, and Exact MS of thecompounds thus obtained are shown below together with the structuralformulae thereof. ##STR18##

(Analytical results of J-1).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.43(dd,1H); 6.42(dd,2H); 6.12(dd,1H);6.11(dd,1H); 6.10(dd,1H); 5.89(dd,2H); 5.88(dd,1H); 5.57-5.64(m,1H);4.46,4.41(ABq,2H); 4.41,4.39(ABq,2H); 4.27,4.23(dABq,2H);2.68-2.31(m,2H); 1.30(s,3H)

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.47;-119.72;-118.91; -118.60;-109.76; -77.79.

Exact MS: Measured value; 772.0969, Theoretical value; C₂₅ H₂₁ F₁₇ O₈ :772.0965. ##STR19##

(Analytical results of J-2).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,1H); 6.42(dd,2H); 6.12(dd,1H);6.11(dd,1H); 6.11(dd,1H); 5.89(dd,1H); 5.88(dd,2H); 5.38-5.34(m,1H);4.43,4.36(ABq,2H); 4.41,4.39(ABq,2H); 4.29,4.13(dABq,2H);2.68-2.31(m,2H); 1.30(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.47;-119.71;-118.91; -118.60;-109.76; -77.78.

Exact MS: Measured value; 772.0962, Theoretical value; C₂₅ H₂₁ F₁₇ O₈:772.0965.

Example 2-2

215 g of white crystal product K (yield 32%) was obtained in the sameway as in Example 2-1 via the compounds of the structures represented bythe formulae (17) and (18), except that 376.1 g (1.0 mol) of3-perfluorohexyl-1,2-epoxypropane was employed instead of3-perfluorooctyl-1,2-epoxypropane.

A portion of product K was separated by high speed liquid chromatographyin the same way as in Example 1-1. The obtained compounds K-1 and K-2were the compounds having the structures represented by the followingformulae (26) and (27), respectively. The results of ¹ H-NMR, ¹⁹ F-NMR,and Exact MS of the compounds thus obtained are shown below togetherwith the structural formulae thereof. ##STR20##

(Analytical results of K-1).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,1H); 6.43(dd,1H); 6.42(dd,1H);6.12(dd,1H); 6.11(dd,1H); 6.10(dd,1H); 5.89(dd,2H); 5.88(dd,1H);5.57-5.64(m,1H); 4.47,4.41(ABq,2H); 4.41,4.39(ABq,2H);4.28,4.23(dABq,2H); 2.68-2.31(m,2H); 1.30(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.09;-120.39;-119.89;-118.89; -109.39;-77.90.

Exact MS: Measured value: 672.1023, Theoretical value: C₂₃ H₂₁ F₁₃ O₈ :672.1029. ##STR21##

(Analytical results of K-2).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.43(dd,1H); 6.42(dd,2H); 6.12(dd,1H);6.11(dd,1H); 6.11(dd,1H); 5.88(dd,1H); 5.87(dd,2H); 5.37-5.34(m,1H);4.43,4.36(ABq,2H); 4.41,4.39(ABq,2H); 3.88,4.75(dABq,2H);2.48-2.21(m,2H); 1.33(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.08; -120.39;-119.88;-118.89; -109.39;-77.90.

Exact MS: Measured value: 672.1018, Theoretical value: C₂₃ H₂₁ F₁₃ O₈ :672.1029.

Example 2-3

Product I was obtained in the same way as in Example 1-3. Into a reactorequipped with a stirrer, a thermometer, a gas introducing tube and adropping funnel, 574 g of the product I, 151.8 g of triethylamine, and1000 ml of chloroform were charged. Under ice cooling, 159.8 g (1.5 mol)of acryloylchloride were dissolved in 150 ml of chloroform, and theresulting solution was added dropwise to the reaction liquid from thedropping funnel while the temperature of the reaction liquid was keptbelow 5° C. After the completion of dropping, the reaction liquid waskept under ice cooling and stirred for two hours. Chloroform was thenremoved from the reaction liquid under reduced pressure, and theobtained yellow crystals were further purified by column chromatographyusing as a developing solvent ethyl acetate/n-hexane mixed solvent (1:4by volume). The solvent was then removed under reduced pressure toobtain 208 g of the objective white crystal product L (yield 27%).

A portion of product L was further separated by high speed liquidchromatography in the same way as in Example 1-1. The compounds L-1 andL-2 obtained as the result of separation were the compounds having thestructures represented by the formulae (24) and (25), respectively. Theresults of ¹ H-NMR, ¹⁹ F-NMR, and Exact MS of the compounds thusobtained are shown below.

(Analytical results of L-1).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.43(dd,1H); 6.42(dd,2H); 6.12(dd,1H);6.11(dd,1H); 6.10(dd,1H); 5.89(dd,2H); 5.88(dd,1H); 5.57-5.64(m,1H);4.46,4.41(ABq,2H); 4.41,4.39(ABq,2H); 4.27,4.23(dABq,2H);2.68-2.31(m,2H); 1.30(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.47;-119.72;-118.91; -118.60;-109.76; -77.79.

Exact MS: Measured value: 772.0969, Theoretical value: C₂₅ H₂₁ F₁₇ O₈ :772.0965.

(Analytical results of L-2).

¹ H-NMR(δ (ppm)CDCl₃ /TMS): 6.44(dd,1H); 6.42(dd,2H); 6.12(dd,1H);6.11(dd,1H); 6.11(dd,1H); 5.89(dd,1H); 5.88(dd,2H); 5.38-5.34(m,1H);4.43,4.36(ABq,2H); 4.41,4.39(ABq,2H); 4.29,4.13(dABq,2H);2.68-2.31(m,2H); 1.30(s,3H).

¹⁹ F-NMR(δ (ppm)CDCl₃ /CFCl₃):-123.10;-120.47;-119.71;-118.91; -118.60;-109.76; -77.78.

Exact MS: Measured value: 772.0962, Theoretical value: C₂₅ H₂₁ F₁₇ O₈ :772.0965.

Synthesis Example 1

Into a reactor equipped with a stirrer, a cooling tube, and a gasintroducing tube, 500 parts by weight of 30% silica sol (trade name"XBA-ST", manufactured by NISSAN CHEMICAL INDUSTRIES CO., LTD.), 100parts by weight of 3-acryloxypropyltrimethoxysilane as a silane couplingagent (trade name "KBM-5103", manufactured by TOSHIBA SILICONE CO.) and20 parts by weight of water were charged, gradually heated up to 100° C.in an oil bath, and stirred at this temperature for 2 hours. The coolingtube was then removed and the mixture was stirred for two hours at theoil bath temperature of 120° C., and then cooled down to the roomtemperature, for obtaining the reaction liquid M. It is believed that,in the reaction liquid M, the silane coupling agent modified a part ofthe surface of colloidal silica. A portion of the reaction liquid M wasput on a Schale, and dried at 120° C. for two hours, and the weightbefore and after the drying was measured for measuring the solidcontent, which was found to be 44.6%.

Preparation Example 1

45 parts by weight of dipentaerythritol hexaacrylate manufactured byHITACHI CHEMICAL CO., LTD., 30 parts by weight of polyethylene glycoldiacrylate (trade name "A-400", manufactured by SHIN-NAKAMURA CHEMICALCO., LTD.), 4 parts by weight of "IRGACURE 184" (trade name,manufactured by CIBA GEIGY LTD.) as a curing initiator, and 20 parts byweight of isopropyl alcohol as a solvent were mixed together, and theobtained mixture was applied to a PET film by a micro gravure coatermanufactured by YASUISEIKI CO., LTD. so that the film thickness was 5μm. The film was cured by irradiating the film with ultraviolet ray byan ultraviolet irradiator manufactured by IWASAKI ELECTRIC CO., LTD. at800 mJ/cm² to form a hard coating, thereby preparing a PET film withhard coating (abbreviated as HC-PET hereinbelow).

Preparation Example 2

A hard coating was formed on a TAC film in the same way as inPreparation Example 1 to prepare a TAC film with hard coating(abbreviated as HC-TAC hereinbelow). Next, 240 parts by weight oftoluene dispersion containing 30% zinc oxide powders (trade name"ZN-300", manufactured by SUMITOMO OSAKA CEMENT CO. LTD.), 28 parts byweight of trimethylolpropane triacrylate (abbreviated as TMPTAhereinbelow), 1 part by weight of "DAROCUR1116" (trade name,manufactured by E. MELCK CORPORATION, acetophenone compound)(abbreviated as "DAROCUR1116" hereinbelow) as a curing initiator, and1900 parts by weight of toluene as a solvent were mixed together toprepare a coating liquid. Subsequently, the coating liquid was appliedto the HC-TAC by dip coating method (at pull-up rate of 100 mm/min.).The applied coating liquid was cured by irradiating with ultraviolet rayby an ultraviolet irradiator at 1000 mJ/cm² to form a layer of a highrefractivity material, thereby preparing a TAC film with a layer of thehigh refractivity material (abbreviated as HR-TAC-A hereinbelow).

Preparation Example 3

A TAC film with a layer of the high refractivity material (abbreviatedas HR-TAC-B hereinbelow) w as prepared in the same way as in PreparationExample 2 except that the dip coating was carried out at the pull-outrate of 130 mm/min.

Examples 4-1 and 4-2

Product G synthesized in Example 1-1 and tetramethylolmethanetetraacrylate (abbreviated as TMMTA hereinbelow) were mixed at themixing ratio set forth in Table 1 to prepare compositions. Each of thecompositions was mixed with 400 parts by weight oftrifluoromethylbenzene to prepare two kinds of coating liquids. Then,each of the coating liquids was applied to HC-PET prepared inPreparation Example 1 with the micro gravure coater. The applied coatingliquids were irradiated with electron beam of the absorbed dose of 15Mrad by an electron beam irradiator (manufactured by IWASAKI ELECTRICCO., LTD.) at the accelerating voltage of 125 kV and the beam current of35 mA to cure the applied compositions, thereby preparing reflectionreducing PET films with a layer of the low refractivity material. Thefilm thickness of the low refractivity material was adjusted with aninstantaneous multi optical measurement system so that the wave lengthwhich indicated the minimum refractivity was 550 to 600 nm. Forevaluation, the films thus obtained were subjected to the measurementsof (a), (b), and (c), and the coating liquids thus obtained weresubjected to the measurement of (d), each specified below.

(a) Spectral Reflectance

The spectral reflectance of the film was measured by an UVSpectrophotometer equipped with 5 degree specular reflectivity measuringattachment (manufactured by JAPAN SPECTROSCOPIC CO., LTD., trade name"U-best 35"). The measurement was effected on the coated surface, andthe opposite surface of the film was roughened with a sandpaper forinhibiting reflection on the opposite surface. The results are shown inFIGS. 1 and 2. The minimum reflectance of each film is shown in Table 1.

(b) Abrasion Resistance

The scratch resistance against #0000 steel wool was measured, andevaluated according to the evaluation standard below. The results areshown in Table 1.

A: No abrasion by vigorous rubbing

B: Slight abrasion by vigorous rubbing

C: Slight abrasion by soft rubbing

D: Remarkable abrasion by soft rubbing

(c) Adhesion

Cross cut test was conducted in accordance with JIS K 5400. The resultsare shown in Table 1.

(d) Refractive Index of the Low Refractivity Material

The coating liquid was applied on a glass plate so that the drythickness of the resulting coating film was 500 μm, and cured byirradiating with electron beam of the absorbed dose of 5 Mrad by anelectron beam irradiator at the accelerating voltage of 175 kV and thebeam current of 5 mA. The film thus obtained was peeled off of the glassplate, and the refractive index of the film was measured using Abbe'srefractometer (manufactured by ATAGO CO., LTD.). The results are shownin Table 1.

Examples 4-3 and 4-4

Product H synthesized in Example 1-2 and TMMTA were mixed together atthe mixing ratio set forth in Table 1 to prepare compositions. Each ofthe compositions was mixed with 400 parts by weight oftrifluoromethylbenzene as a solvent to prepare two kinds of coatingliquids. Then, each of the coating liquids was applied to HC-PETprepared in Preparation Example 1 with the micro gravure coater. Theapplied coating liquids were irradiated with electron beam of theabsorbed dose of 15 Mrad by the electron beam irradiator to cure theapplied compositions, thereby preparing reflection reducing PET filmswith a layer of the low refractivity material. The film thickness of thelow refractivity material was adjusted in the same way as in Examples4-1 and 4-2. The coating liquids and the reflection reducing films thusobtained were subjected to the same evaluation tests for spectralreflectance, minimum reflection, adhesion, abrasion resistance andrefractive index as in Examples 4-1 and 4-2. The results are shown inFIGS. 3 and 4 and Table 1.

Examples 4-5 and 4-6

Product G, TMMTA, 10% magnesium fluoride sol (trade name "MFS-10P"manufacture by NISSAN CHEMICAL INDUSTRIES CO., LTD.; referred tohereinbelow as "MFS-10P"), and DAROCUR 1116 were mixed together at themixing ratio set forth in Table 1 to prepare compositions. Each of thecompositions was mixed with 400 parts by weight oftrifluoromethylbenzene as a solvent to prepare two kinds of coatingliquids. Then, each of the coating liquids was applied to HR-TAC-Aprepared in Preparation Example 2 with the micro gravure coater. Theapplied coating liquids were irradiated three times with ultraviolet rayby an ultraviolet irradiator at 1000 mJ/cm² to cure the appliedcompositions, thereby preparing reflection reducing TAC films withlaminated layers of the low refractivity material and the highrefractivity material. The film thickness of the low refractivitymaterial was adjusted in the same way as in Examples 4-1 and 4-2. Thecoating liquids and the reflection reducing films thus obtained weresubjected to the same evaluation tests for spectral reflectance, minimumreflection, adhesion, abrasion resistance, and refractive index as inExamples 4-1 and 4-2. The results are shown in FIGS. 5 and 6 and Table1.

Examples 4-7 and 4-8

Product G, 4,4,5,5,6,6,7,7-octafluorodecan-1,2,9,10-tetraoltetraacrylate (abbreviated as F₈ DTA hereinbelow), the reaction liquid Mand DAROCUR 1116 were mixed together at the mixing ratio set forth inTable 1 to prepare compositions. Each of the compositions was mixed with400 parts by weight of trifluoromethylbenzene as a solvent to preparetwo kinds of coating liquids. Then, each of the coating liquids wasapplied to HR-TAC-B prepared in Preparation Example 3 with the microgravure coater. The applied coating liquids were irradiated three timeswith ultraviolet ray by an ultraviolet irradiator at 1000 mJ/cm² to curethe applied compositions, thereby preparing reflection reducing TACfilms with laminated layers of the low refractivity material and thehigh refractivity material. The film thickness of the low refractivitymaterial was adjusted in the same way as in Examples 4-1 and 4-2. Thecoating liquids and the reflection reducing films thus obtained weresubjected to the same evaluation tests for spectral reflectance, minimumreflection, adhesion, abrasion resistance, and refractive index as inExamples 4-1 and 4-2. The results are shown in FIGS. 7 and 8 and Table1.

Comparative Examples 1 and 2

The spectral reflectance, the minimum reflection, and the abrasionresistance of HC-PET and HC-TAC prepared in Preparation Examples 1 and2, respectively, were measured in the same way as in Examples 4-1 and4-2. The results are shown in FIGS. 9 and 10 and Table 1.

Comparative Example 3

2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononylethylene glycoldiacrylate (abbreviated as F₁₇ EDA hereinbelow) and TMMTA were mixed atthe mixing ratio set forth in Table 1, and further mixed with 400 partsby weight of trifluoromethylbenzene as a solvent to prepare a coatingliquid. Then the coating liquid thus obtained was applied to HC-PETprepared in Preparation Example 1 with the micro gravure coater. Theapplied coating liquid was irradiated with electron beam of the absorbeddose of 15 Mrad by the electron beam irradiator at the acceleratingvoltage of 125 kV and the beam current of 35 mA to cure the appliedcoating liquid, thereby preparing a reflection reducing PET film with alayer of the low refractivity material. The film thickness of the lowrefractivity material was adjusted in the same way as in Examples 4-1and 4-2. The coating liquid and the reflection reducing film thusobtained were subjected to the same evaluation tests for spectralreflectance, minimum reflection, adhesion, abrasion resistance andrefractive index, as in Examples 4-1 and 4-2. The results are shown inFIG. 11 and Table 1.

Comparative Example 4

F₈ DTA and TMMTA were mixed at the mixing ratio set forth in Table 1,and further mixed with 400 parts by weight of trifluoromethylbenzene asa solvent to prepare a coating liquid. Then, the coating liquid wasapplied to HC-PET prepared in Preparation Example 1 with the microgravure coater. The applied coating liquid was irradiated with electronbeam of the absorbed dose of 15 Mrad by the electron beam irradiator atthe accelerating voltage of 125 kV and beam current of 35 mA to cure theapplied mixture, thereby preparing a reflection reducing PET film with alayer of the low refractivity material. The film thickness of the lowrefractivity material was adjusted in the same way as in Examples 4-1and 4-2. The coating liquid and the reflection reducing film thusobtained were subjected to the same evaluation tests for spectralreflectance, minimum reflection, adhesion, abrasion resistance andrefractive index as in Examples 4-1 and 4-2. The results are shown inFIG. 12 and Table 1.

                                      TABLE 1                                     __________________________________________________________________________               Fulorine-                                                                             Fluorine-                                                    containing containing                                                         bifunctional monomer Poly-                                                             monomer tetra-                                                                            bi- func-                                                containing OH func- func- tional  Curing                                      group tional tional monomer Inorganic powders initiator                                Product                                                                           Product                                                                           F.sub.8 DTA                                                                       F.sub.17 EDA                                                                      TMMTA     Reaction                                                                           D.1116                                 G H parts parts parts MFS-10P liquid M parts Minimum  Scratch Refrac-                                                                  Substrate                                                                    parts by parts                                                                by by by by                                                                   parts by parts                                                                by by reflec-                                                                 Adhe- resis-                                                                  tive                 film weight weight weight weight weight weight weight weight tion sion                                                                 tance index        __________________________________________________________________________    Ex. 4-1                                                                            HC-PET                                                                              70  --  --  --  30   --   --   --  1.5  100/100                                                                           C   1.446                Ex. 4-2 HC-PET 30 -- -- -- 70 -- -- -- 2.0 100/100 B 1.474                    Ex. 4-3 HC-PET -- 70 -- -- 30 -- -- -- 1.5 100/100 C 1.448                    Ex. 4-4 HC-PET -- 40 -- -- 60 -- -- -- 2.0 100/100 B 1.472                    Ex. 4-5 HR-TAC-A 20 -- -- -- 80 30 -- 1 0.5 100/100 B 1.447                   Ex. 4-6 HR-TAC-A 25 -- -- -- 85 15 -- 1 0.6 100/100 A 1.465                   Ex. 4-7 HR-TAC-B 50 -- 20 -- -- -- 60 1 0.7 100/100 B 1.446                   Ex. 4-8 HR-TAC-B 10 -- 50 -- -- -- 80 1 0.9 100/100 A 1.446                   Comp. HC-PET -- -- -- -- -- -- -- -- 2.4 -- A --                              Ex. 1                                                                         Comp. HC-TAC -- -- -- -- -- -- -- -- 4.0 -- A --                              Ex. 2                                                                         Comp. HC-PET -- -- -- 70 30 -- -- -- 1.1  30/100 D 1.421                      Ex. 3                                                                         Comp. HC-PET -- -- 70 -- 30 -- -- -- 1.8  40/100 A 1.467                      Ex. 4                                                                       __________________________________________________________________________

Examples 5-1 and 5-2

Product J synthesized in Example 2-1 and TMMTA were mixed at the mixingratio set forth in Table 2 to prepare compositions. Each of thecompositions was mixed with 400 parts by weight oftrifluoromethylbenzene to prepare two kinds of coating liquids. Then,each of the coating liquids was applied to HC-PET prepared inPreparation Example 1 with the micro gravure coater. The applied coatingliquids were irradiated with electron beam of the absorbed dose of 15Mrad by an electron beam irradiator (manufactured by IWASAKI ELECTRICCO., LTD.) at the accelerating voltage of 125 kV and the beam current of35 mA to cure the applied compositions, thereby preparing reflectionreducing PET films with a layer of the low refractivity material. Thefilm thickness of the low refractivity material was adjusted in the sameway as in Examples 4-1 and 4-2. The coating liquids and the reflectionreducing films thus obtained were subjected to the same evaluation testsfor spectral reflectance, minimum reflection, abrasion resistance andrefractive index as in Examples 4-1 and 4-2. The results are shown inFIGS. 13 and 14 and Table 2.

Examples 5-3 and 5-4

Product K synthesized in Example 2-2 and TMMTA were mixed together atthe mixing ratio set forth in Table 2 to prepare compositions. Each ofthe compositions was mixed with 400 parts by weight oftrifluoromethylbenzene as a solvent to prepare two kinds of coatingliquids. Then, each of the coating liquids was applied to HC-PETprepared in Preparation Example 1 with the micro gravure coater. Theapplied coating liquids were irradiated with electron beam of theabsorbed dose of 15 Mrad by an electron beam irradiator (manufactured byIWASAKI ELECTRIC CO., LTD.) at the accelerating voltage of 125 kV andthe beam current of 35 mA to cure the applied compositions, therebypreparing reflection reducing PET films with a layer of the lowrefractivity material. The film thickness of the low refractivitymaterial was adjusted in the same way as in Examples 4-1 and 4-2. Thecoating liquids and the reflection reducing films thus obtained weresubjected to the same evaluation tests for spectral reflectance, minimumreflection, abrasion resistance and refractive index as in Examples 4-1and 4-2. The results are shown in FIGS. 15 and 16 and Table 2.

Examples 5-5 and 5-6

Product J, TMMTA, MFS-10P and DOROCUR 1116 were mixed together at themixing ratio set forth in Table 2 to prepare compositions. Each of thecompositions was mixed with 400 parts by weight oftrifluoromethylbenzene as a solvent to prepare two kinds of coatingliquids. Then, each of the coating liquids was applied to HR-TAC-Aprepared in Preparation Example 2 with the micro gravure coater. Each ofthe applied coating liquids was irradiated three times with ultravioletray by an ultraviolet irradiator at 1000 mJ/cm² to cure the coatingliquid, thereby preparing reflection reducing films with a layer of thelow refractivity material. The film thickness of the low refractivitymaterial was adjusted in the same way as in Examples 4-1 and 4-2. Thecoating liquids and the reflection reducing films thus obtained weresubjected to the same evaluation tests for spectral reflectance, minimumreflection, abrasion resistance and refractive index as in Examples 4-1and 4-2. The results are shown in FIGS. 17 and 18 and Table 2.

Examples 5-7 and 5-8

Product J, TMMTA, reaction liquid M and DOROCUR 1116 were mixed togetherat the mixing ratio set forth in Table 2 to prepare compositions. Eachof the compositions was mixed with 400 parts by weight oftrifluoromethylbenzene as a solvent to prepare two kinds of coatingliquids. Then, each of the coating liquids was applied to HR-TAC-Bprepared in Preparation Example 3 with the micro gravure coater. Each ofthe applied coating liquids was irradiated three times with ultravioletray by an ultraviolet irradiator at 1000 mJ/cm² to cure the coatingliquid, thereby preparing reflection reducing films with a layer of thelow refractivity material. The film thickness of the low refractivitymaterial was adjusted in the same way as in Examples 4-1 and 4-2. Thecoating liquids and the reflection reducing films thus obtained weresubjected to the same evaluation tests for spectral reflectance, minimumreflection, abrasion resistance and refractive index as in Examples 4-1and 4-2. The results are shown in FIGS. 19 and 20 and Table 2.

Comparative Example 5

100 parts by weight of heptadecafluorodecyl acrylate (abbreviated as F₁₇A hereinbelow ) and 400 parts by weight of trifluoromethylbenzene as asolvent were mixed together to prepare a coating liquid. Then, thecoating liquid was applied to HC-PET prepared in Preparation Example 1with the micro gravure coater. The applied coating liquid was irradiatedwith electron beam of the absorbed dose of 15 Mrad by an electron beamirradiator (manufactured by IWASAKI ELECTRIC CO., LTD.) at theaccelerating voltage of 125 kV and the beam current of 35 mA to cure theapplied composition, thereby preparing a reflection reducing PET filmwith a layer of the low refractivity material. The film thickness of thelow refractivity material was adjusted in the same way as in theExamples 4-1 and4-2. The coating liquid and the reflection reducing filmthus obtained were subjected to the same evaluation tests for spectralreflectance, minimum reflection, abrasion resistance and refractiveindex as in Examples 4-1 and 4-2. The results are shown in FIG. 21 andTable 2.

Comparative Examples 6 and 7

100 parts by weight of either F₁₇ EDA or TMMTA was mixed with 400 partsby weight of trifluoromethylbenzene as a solvent to prepare two kinds ofcoating liquids. Each of the coating liquids was applied to HR-TAC-Aprepared in Preparation Example 3 with the micro gravure coater. Each ofthe applied coating liquids was irradiated three times with ultravioletray by an ultraviolet irradiator at 1000 mJ/cm² to cure the coatingliquid, thereby preparing reflection reducing films with a layer of thelow refractivity material. The film thickness of the low refractivitymaterial was adjusted in the same way as in Examples 4-1 and 4-2. Thecoating liquids and the reflection reducing films thus obtained weresubjected to the same evaluation tests for spectral reflectance, minimumreflection, abrasion resistance and refractive index as in Examples 4-1and 4-2. The results are shown in FIGS. 22 and Table 2.

Comparative Examples 8 to 10

F₁₇ EDA and TMMTA were mixed at the mixing ration set forth in Table 2.However, none of these were compatible and became turbid in white.

                                      TABLE 2                                     __________________________________________________________________________                        Fluorine-                                                    containing                                                                   Fluorine- monomer Poly-                                                                 containing                                                                            tetra-                                                                            bi- func-                                               trifunctional func- func- tional  Curing                                      monomer tional tional monomer Inorganic powders initiator                               Product                                                                           Product                                                                           F.sub.17 A                                                                        F.sub.17 EDA                                                                      TMMTA      Reaction                                                                            D.1116                              J K parts parts parts MFS-10P liquid M parts Minimum Scratch Refrac-                                                                   Substrate                                                                    parts by parts                                                                by by by by                                                                   parts by parts                                                                by by reflec-                                                                 resis- tive                                                                    film weight                                                                  weight weight                                                                 weight weight                                                                 weight weight                                                                 weight tion                                                                   tance index        __________________________________________________________________________    Ex. 5-1                                                                             HC-PET                                                                              70  --  --  --  30    --   --    --  1.5   C   1.447                Ex. 5-2 HC-PET 30 -- -- -- 70 -- -- -- 1.9 B 1.473                            Ex. 5-3 HC-PET -- 70 -- -- 30 -- -- -- 1.5 C 1.447                            Ex. 5-4 HC-PET -- 30 -- -- 70 -- -- -- 2.0 B 1.483                            Ex. 5-5 HR-TAC-A 40 -- -- -- 40 150  -- 1 0.5 B 1.448                         Ex. 5-6 HR-TAC-A 30 -- -- -- 50 100 -- 1 0.6 A 1.464                          Ex. 5-7 HR-TAC-B 80 -- -- -- 20 -- 60 1 0.7 B 1.443                           Ex. 5-8 HR-TAC-B 40 -- -- -- 40 -- 80 1 0.9 A 1.474                           Comp. Ex. 5 HC-PET -- -- 100 -- -- -- -- -- 0.4 D 1.364                       Comp. Ex. 6 HR-TAC-A -- -- -- -- 100  -- -- -- 1.0 B 1.505                    Comp. Ex. 7 HR-TAC-A -- -- -- 100  -- -- -- -- 0.3 D 1.388                  Comp. Ex. 8 --  --  --  70  30    --   --    --  Not compatible                 Comp. Ex. 9  -- -- -- 50 50 -- -- -- Not compatible                           Comp. Ex.  -- -- -- 30 70 -- -- -- Not compatib1e                             10                                                                          __________________________________________________________________________

What is claimed is:
 1. Fluorine-containing polyfunctional (meth)acrylate represented by the formula (1): ##STR22## wherein X stands for a fluoroalkyl group having 1 to 14 carbon atoms and 3 or more fluorine atoms, or a fluorocycloalkyl group having 3 to 14 carbon atoms and 4 or more fluorine atoms; Y¹, Y², and Y³ stand for a hydrogen atom, an acryloyl group or a methacryloyl group, and at least two of Y¹, Y², and Y³ are the same or different groups and stand for an acryloyl group or a methacryloyl group; Z stands for a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; and n and m is an integer of 0 or 1, and n+m=1.
 2. The fluorine-containing polyfunctional (meth)acrylate as claimed in claim 1 wherein n=1 and m=0 and wherein said fluorine-containing polyfunctional (meth)acrylate is selected from the group consisting of fluorine-containing bifunctional (meth)acrylate having (meth)acryloyl groups and a hydroxyl group in which two of Y¹, Y² and Y³ stand for an acryloyl group or a methacryloyl group, and the remaining one of Y¹, Y² and Y³ stands for a hydrogen atom; and fluorine-containing trifunctional (meth)acrylate in which Y¹, Y² and Y³ are the same or different groups and stand for an acryloyl group or a methacryloyl group.
 3. The fluorine-containing polyfunctional (meth)acrylate as claimed in claim 1 wherein n=0 and m=1 and wherein said fluorine-containing polyfunctional (meth)acrylate is selected from the group consisting of fluorine-containing bifunctional (meth)acrylate having (meth)acryloyl groups and a hydroxyl group in which two of Y¹, Y² and Y³ stand for an acryloyl group or a methacryloyl group, and the remaining one of Y¹, Y² and Y³ stands for a hydrogen atom; and fluorine-containing trifunctional (meth)acrylate in which Y¹, Y² and Y³ are the same or different groups and stand for an acryloyl group or a methacryloyl group.
 4. A composition comprising 5 to 100% by weight of said fluorine-containing polyfunctional (meth)acrylate as claimed in claim
 1. 5. The composition as claimed in claim 4 further comprising powders of an inorganic compound.
 6. A low refractivity material having refractive index of 1.49 or lower prepared by a method comprising the step of curing said composition as claimed in claim 4 or 5 by polymerization.
 7. A reflection reducing film comprising a transparent substrate and a layer of said low refractivity material as claimed in claim
 6. 8. The reflection reducing film as claimed in claim 7 further comprising a hard coating for improving abrasion resistance.
 9. The reflection reducing film as claimed in claim 7 further comprising at least one material layer between the transparent substrate and the layer of the low refractivity material.
 10. The reflection reducing film as claimed in claim 9 wherein said material layer is a layer of a high refractivity material having refractive index of 1.55 or higher. 